Evaluation of different carbonate sources for bicarbonate-based integrated carbon capture and algae production system using Spirulina platensis

Abstract

Spirulina Platensis was evaluated in Bicarbonate-based Integrated Carbon Capture and Algae Production System (BICCAPS) using Modified Zarrouk’s media under three different carbonate solutions, namely, sodium, potassium and an equimolar mixture of sodium-potassium carbonate, as well as a control experiment consisting of only water. All systems mentioned were exposed to carbon dioxide loading in order to produce bicarbonate solutions to be used for cultivation of Spirulina Platensis under BICCAPS. Parameters such as pH, biomass productivity, and carbon conversion were analyzed to evaluate the effectivity of BICCAPS as a carbon sequestration technique given the conditions applied in the study. Results determined that the control system produced the highest biomass productivity of 10.42 mg L−1 day−1 despite having the lowest carbon conversion of 0.292 mM due to the limited amount of bicarbonates initially present. The sodium-potassium carbonate system then follows the control experiment, having a productivity of 7.37 mg L−1 day−1 and carbon conversion of 4.192 mM. Sodium carbonate system ranks third with productivity and carbon conversion of 6.56 mg L−1 day−1 and 2.682 mM. Lastly, potassium carbonate system was determined to have the lowest productivity of 4.48 mg −1 day−1 as well as a relatively low carbon conversion of 0.996 mM.